Where would I start the search?

I'd expand your search a bit and give a chance to some of the neighborhoods that maybe aren't quite the fun, trendy neighborhoods, but are close to them.  

I'm curious as to what the best strategies are for identifying potential properties, how to approach the homeowners (letter, door to door, a written offer, etc) and how to write a fair and solid price (I'm thinking full price offer based on comps minus 6% because of no commission but throwing in some cash or creditiing closing costs to the seller to sweeten the deal a little bit. 

Use these venues to ask questions about what you’re learning.Narrow your focus - If you plan to invest identify where you would like to start.

You hadn't disclosed your intent for the property, but for resale or rental, it would be good to just look at the quality of similar properties, then try to match or slightly go a step up, in order to increase your ROI.Once you've identified what it is you really value currently, it's best to get 3 estimates and see if you're getting the same values for each. 

Just an initial in-depth search on Zillow, MLS, BP, Auction.com..etc, we have noticed that there are not so many properties that we could get that would give us a good cash flow.

I’ve done forum searches, but still have questions.I’ve done only two all-cash deals so far for small multi-family properties and I’m ready to dip into borrowing.

"Lift" if you want to google search it.

Could anyone give me some tips about how to input the PMI in the expense side of the things on this online tool to better identify if this is the right deal for me?  

It claims to be able to identify prime areas for your needs, and show cash on cash returns for both airbnb and traditional.